The present invention concerns a filter element as well as a filter arrangement for filtering fluids such as, for example, liquid operating media for motor vehicles. A filter element is received in a filter receptacle or a filter housing so that, as a whole, a filter system or a filter arrangement is provided.
In the automotive field, liquid operating media are often employed, such as, for example, fuels like gasoline and diesel, lubricants like oil, or also urea solutions, and contaminants must be removed from them. For this purpose, usually filter elements are employed that are inserted into a filter housing or a filter receptacle. The filter elements themselves comprise in this context mostly a flat and folded filter medium which is provided between end disks or end caps and is radially flowed through. Known are in particular cylindrical housing and filter element geometries. Mostly, as a result of the installation situations, geometric specifications must be met by the respective filter element, the filter receptacle, and the supply and discharge lines for clean and raw fluid. It is desirable to employ in a small installation space a filter surface area as large as possible.
DE 198 56 723 A1 discloses a filter insert for a fuel filter comprising an inlet and an outlet wherein the filter insert comprises a filter material bellows that, in cross-section, is C-shaped and folded in a star shape and which is sealed on all sides by two flat end face covers in the form of circular sectors and by a rectangular lateral cover. The filter insert can be arranged in a space-saving way in a housing with a D-shaped cross-section.
The publication DE 20 2009 000 969 U1 discloses a filter element with a ring-shaped closed folded filter medium whose end faces are connected seal-tightly with end disks. The fold height between neighboring folds increases or decreases across several folds. In this way, the filter element can be integrated into installation spaces with special geometries.
WO 2007/081425 A1 describes filter elements with folded filter media wherein the folds extend along a longitudinal axis and a transverse axis extending transverse thereto between first and second fold tips. The fold depth varies along an axis which is normal to the fold planes.